From: Shuo A Liu <shuo.a.liu@intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
"H . Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Yu Wang <yu1.wang@intel.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Zhi Wang <zhi.a.wang@intel.com>,
Zhenyu Wang <zhenyuw@linux.intel.com>
Subject: Re: [PATCH v4 06/17] virt: acrn: Introduce VM management interfaces
Date: Mon, 28 Sep 2020 14:29:34 +0800 [thread overview]
Message-ID: <20200928062934.GF1057@shuo-intel.sh.intel.com> (raw)
In-Reply-To: <20200928052516.GD767987@kroah.com>
On Mon 28.Sep'20 at 7:25:16 +0200, Greg Kroah-Hartman wrote:
>On Mon, Sep 28, 2020 at 11:50:30AM +0800, Shuo A Liu wrote:
>> > > + write_lock_bh(&acrn_vm_list_lock);
>> > > + list_add(&vm->list, &acrn_vm_list);
>> > > + write_unlock_bh(&acrn_vm_list_lock);
>> >
>> > Why are the _bh() variants being used here?
>> >
>> > You are only accessing this list from userspace context in this patch.
>> >
>> > Heck, you aren't even reading from the list, only writing to it...
>>
>> acrn_vm_list is read in a tasklet which dispatch I/O requests and is wrote
>> in VM creation ioctl. Use the rwlock mechanism to protect it.
>> The reading operation is introduced in the following patches of this
>> series. So i keep the lock type at the moment of introduction.
>
>Ok, but think about someone trying to review this code. Does this lock
>actually make sense here? No, it does not. How am I supposed to know
>to look at future patches to determine that it changes location and
>usage to require this?
OK. May i know how to handle such kind of code submission? Or which way
following do you prefer?
1) Use a mutex lock here, then change it to rwlock in a later patch
of this series.
2) Add more comments in changelog about the lock. (Now, there is
comment around the acrn_vm_list_lock)
>
>That's just not fair, would you want to review something like this?
>
>And a HUGE meta-comment, again, why am I the only one reviewing this
>stuff? Why do you have a ton of Intel people on the Cc: yet it is, once
>again, my job to do this?
The patchset has been reviewed in Intel's internal mailist several
rounds and got Reviewed-by: before send out. That's why i Cced many
Intel people as well.
This patchset is all about a common driver for the ACRN hypervisor
support. I put the code in drivers/virt/ and found you are one of the
maintainer of vboxguest driver which is in the same subdirectory. I
thought you should be the right person to be Cced when i submitted this
series.
Certainly, any comments are welcome. And really appreciate your review
and help. I have little experience to submit a new driver to the
community, my apologies if thing goes wrong.
Thanks
shuo
next prev parent reply other threads:[~2020-09-28 6:29 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 11:42 [PATCH v4 00/17] HSM driver for ACRN hypervisor shuo.a.liu
2020-09-22 11:42 ` [PATCH v4 01/17] docs: acrn: Introduce ACRN shuo.a.liu
2020-10-09 1:48 ` Randy Dunlap
2020-10-12 8:50 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 02/17] x86/acrn: Introduce acrn_{setup, remove}_intr_handler() shuo.a.liu
2020-09-27 10:49 ` Greg Kroah-Hartman
2020-09-28 3:28 ` Shuo A Liu
2020-09-29 18:01 ` Borislav Petkov
2020-09-29 20:07 ` Thomas Gleixner
2020-09-29 20:26 ` Borislav Petkov
2020-09-30 3:02 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 03/17] x86/acrn: Introduce an API to check if a VM is privileged shuo.a.liu
2020-09-30 8:09 ` Borislav Petkov
2020-10-12 8:40 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 04/17] x86/acrn: Introduce hypercall interfaces shuo.a.liu
2020-09-27 10:51 ` Greg Kroah-Hartman
2020-09-27 10:53 ` Greg Kroah-Hartman
2020-09-28 3:38 ` Shuo A Liu
2020-09-27 15:38 ` Dave Hansen
2020-09-30 11:16 ` Peter Zijlstra
2020-09-30 16:10 ` Segher Boessenkool
2020-09-30 17:13 ` Peter Zijlstra
2020-09-30 19:14 ` Nick Desaulniers
2020-09-30 19:42 ` Peter Zijlstra
2020-09-30 23:58 ` Segher Boessenkool
2020-09-30 19:59 ` Arvind Sankar
2020-09-30 20:01 ` Arvind Sankar
2020-10-01 0:08 ` Segher Boessenkool
2020-09-30 23:25 ` Segher Boessenkool
2020-09-30 23:38 ` Arvind Sankar
2020-10-01 0:11 ` Segher Boessenkool
2020-10-12 8:44 ` Shuo A Liu
2020-10-12 16:49 ` Arvind Sankar
2020-10-13 2:44 ` Shuo A Liu
2020-09-30 10:54 ` Borislav Petkov
2020-10-12 8:49 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 05/17] virt: acrn: Introduce ACRN HSM basic driver shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 08/17] virt: acrn: Introduce EPT mapping management shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 10/17] virt: acrn: Introduce PCI configuration space PIO accesses combiner shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 11/17] virt: acrn: Introduce interfaces for PCI device passthrough shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 12/17] virt: acrn: Introduce interrupt injection interfaces shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 14/17] virt: acrn: Introduce I/O ranges operation interfaces shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 16/17] virt: acrn: Introduce irqfd shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 17/17] virt: acrn: Introduce an interface for Service VM to control vCPU shuo.a.liu
2020-09-27 10:44 ` Greg Kroah-Hartman
2020-09-28 4:10 ` Shuo A Liu
2020-09-28 5:23 ` Greg Kroah-Hartman
2020-09-28 6:33 ` Shuo A Liu
2020-09-27 0:24 ` [PATCH v4 00/17] HSM driver for ACRN hypervisor Liu, Shuo A
2020-09-27 5:42 ` Greg Kroah-Hartman
[not found] ` <20200922114311.38804-7-shuo.a.liu@intel.com>
2020-09-27 10:45 ` [PATCH v4 06/17] virt: acrn: Introduce VM management interfaces Greg Kroah-Hartman
2020-09-28 3:43 ` Shuo A Liu
2020-09-27 10:47 ` Greg Kroah-Hartman
2020-09-28 3:50 ` Shuo A Liu
2020-09-28 5:25 ` Greg Kroah-Hartman
2020-09-28 6:29 ` Shuo A Liu [this message]
2020-09-28 12:26 ` Greg Kroah-Hartman
2020-09-30 2:49 ` Shuo A Liu
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